unsigned char clientid[6];
};
-struct X11Private {
+struct X11Connection {
const struct plug_function_table *fn;
/* the above variable absolutely *must* be the first in this structure */
unsigned char firstpkt[12]; /* first X data packet */
+ tree234 *authtree;
struct X11Display *disp;
char *auth_protocol;
unsigned char *auth_data;
int data_read, auth_plen, auth_psize, auth_dlen, auth_dsize;
int verified;
int throttled, throttle_override;
- unsigned long peer_ip;
+ int no_data_sent_to_x_client;
+ char *peer_addr;
int peer_port;
- void *c; /* data used by ssh.c */
+ struct ssh_channel *c; /* channel structure held by ssh.c */
Socket s;
};
static int dummy_plug_receive(Plug p, int urgent, char *data, int len)
{ return 1; }
static void dummy_plug_sent(Plug p, int bufsize) { }
-static int dummy_plug_accepting(Plug p, OSSocket sock) { return 1; }
+static int dummy_plug_accepting(Plug p, accept_fn_t constructor, accept_ctx_t ctx) { return 1; }
static const struct plug_function_table dummy_plug = {
dummy_plug_log, dummy_plug_closing, dummy_plug_receive,
dummy_plug_sent, dummy_plug_accepting
};
-struct X11Display *x11_setup_display(char *display, int authtype, Conf *conf)
+struct X11FakeAuth *x11_invent_fake_auth(tree234 *authtree, int authtype)
+{
+ struct X11FakeAuth *auth = snew(struct X11FakeAuth);
+ int i;
+
+ /*
+ * This function has the job of inventing a set of X11 fake auth
+ * data, and adding it to 'authtree'. We must preserve the
+ * property that for any given actual authorisation attempt, _at
+ * most one_ thing in the tree can possibly match it.
+ *
+ * For MIT-MAGIC-COOKIE-1, that's not too difficult: the match
+ * criterion is simply that the entire cookie is correct, so we
+ * just have to make sure we don't make up two cookies the same.
+ * (Vanishingly unlikely, but we check anyway to be sure, and go
+ * round again inventing a new cookie if add234 tells us the one
+ * we thought of is already in use.)
+ *
+ * For XDM-AUTHORIZATION-1, it's a little more fiddly. The setup
+ * with XA1 is that half the cookie is used as a DES key with
+ * which to CBC-encrypt an assortment of stuff. Happily, the stuff
+ * encrypted _begins_ with the other half of the cookie, and the
+ * IV is always zero, which means that any valid XA1 authorisation
+ * attempt for a given cookie must begin with the same cipher
+ * block, consisting of the DES ECB encryption of the first half
+ * of the cookie using the second half as a key. So we compute
+ * that cipher block here and now, and use it as the sorting key
+ * for distinguishing XA1 entries in the tree.
+ */
+
+ if (authtype == X11_MIT) {
+ auth->proto = X11_MIT;
+
+ /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
+ auth->datalen = 16;
+ auth->data = snewn(auth->datalen, unsigned char);
+ auth->xa1_firstblock = NULL;
+
+ while (1) {
+ for (i = 0; i < auth->datalen; i++)
+ auth->data[i] = random_byte();
+ if (add234(authtree, auth) == auth)
+ break;
+ }
+
+ auth->xdmseen = NULL;
+ } else {
+ assert(authtype == X11_XDM);
+ auth->proto = X11_XDM;
+
+ /* XDM-AUTHORIZATION-1. Cookie size is 16 bytes; byte 8 is zero. */
+ auth->datalen = 16;
+ auth->data = snewn(auth->datalen, unsigned char);
+ auth->xa1_firstblock = snewn(8, unsigned char);
+ memset(auth->xa1_firstblock, 0, 8);
+
+ while (1) {
+ for (i = 0; i < auth->datalen; i++)
+ auth->data[i] = (i == 8 ? 0 : random_byte());
+ memcpy(auth->xa1_firstblock, auth->data, 8);
+ des_encrypt_xdmauth(auth->data + 9, auth->xa1_firstblock, 8);
+ if (add234(authtree, auth) == auth)
+ break;
+ }
+
+ auth->xdmseen = newtree234(xdmseen_cmp);
+ }
+ auth->protoname = dupstr(x11_authnames[auth->proto]);
+ auth->datastring = snewn(auth->datalen * 2 + 1, char);
+ for (i = 0; i < auth->datalen; i++)
+ sprintf(auth->datastring + i*2, "%02x",
+ auth->data[i]);
+
+ auth->disp = NULL;
+ auth->share_cs = auth->share_chan = NULL;
+
+ return auth;
+}
+
+void x11_free_fake_auth(struct X11FakeAuth *auth)
+{
+ if (auth->data)
+ smemclr(auth->data, auth->datalen);
+ sfree(auth->data);
+ sfree(auth->protoname);
+ sfree(auth->datastring);
+ sfree(auth->xa1_firstblock);
+ if (auth->xdmseen != NULL) {
+ struct XDMSeen *seen;
+ while ((seen = delpos234(auth->xdmseen, 0)) != NULL)
+ sfree(seen);
+ freetree234(auth->xdmseen);
+ }
+ sfree(auth);
+}
+
+int x11_authcmp(void *av, void *bv)
+{
+ struct X11FakeAuth *a = (struct X11FakeAuth *)av;
+ struct X11FakeAuth *b = (struct X11FakeAuth *)bv;
+
+ if (a->proto < b->proto)
+ return -1;
+ else if (a->proto > b->proto)
+ return +1;
+
+ if (a->proto == X11_MIT) {
+ if (a->datalen < b->datalen)
+ return -1;
+ else if (a->datalen > b->datalen)
+ return +1;
+
+ return memcmp(a->data, b->data, a->datalen);
+ } else {
+ assert(a->proto == X11_XDM);
+
+ return memcmp(a->xa1_firstblock, b->xa1_firstblock, 8);
+ }
+}
+
+struct X11Display *x11_setup_display(const char *display, Conf *conf)
{
struct X11Display *disp = snew(struct X11Display);
char *localcopy;
- int i;
if (!display || !*display) {
localcopy = platform_get_x_display();
char *colon, *dot, *slash;
char *protocol, *hostname;
- colon = strrchr(localcopy, ':');
+ colon = host_strrchr(localcopy, ':');
if (!colon) {
sfree(disp);
sfree(localcopy);
disp->port = 6000 + disp->displaynum;
disp->addr = name_lookup(disp->hostname, disp->port,
- &disp->realhost, conf, ADDRTYPE_UNSPEC);
+ &disp->realhost, conf, ADDRTYPE_UNSPEC,
+ NULL, NULL);
if ((err = sk_addr_error(disp->addr)) != NULL) {
sk_addr_free(disp->addr);
disp->port = 0;
}
- /*
- * Invent the remote authorisation details.
- */
- if (authtype == X11_MIT) {
- disp->remoteauthproto = X11_MIT;
-
- /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
- disp->remoteauthdata = snewn(16, unsigned char);
- for (i = 0; i < 16; i++)
- disp->remoteauthdata[i] = random_byte();
- disp->remoteauthdatalen = 16;
-
- disp->xdmseen = NULL;
- } else {
- assert(authtype == X11_XDM);
- disp->remoteauthproto = X11_XDM;
-
- /* XDM-AUTHORIZATION-1. Cookie size is 16 bytes; byte 8 is zero. */
- disp->remoteauthdata = snewn(16, unsigned char);
- for (i = 0; i < 16; i++)
- disp->remoteauthdata[i] = (i == 8 ? 0 : random_byte());
- disp->remoteauthdatalen = 16;
-
- disp->xdmseen = newtree234(xdmseen_cmp);
- }
- disp->remoteauthprotoname = dupstr(x11_authnames[disp->remoteauthproto]);
- disp->remoteauthdatastring = snewn(disp->remoteauthdatalen * 2 + 1, char);
- for (i = 0; i < disp->remoteauthdatalen; i++)
- sprintf(disp->remoteauthdatastring + i*2, "%02x",
- disp->remoteauthdata[i]);
-
/*
* Fetch the local authorisation details.
*/
void x11_free_display(struct X11Display *disp)
{
- if (disp->xdmseen != NULL) {
- struct XDMSeen *seen;
- while ((seen = delpos234(disp->xdmseen, 0)) != NULL)
- sfree(seen);
- freetree234(disp->xdmseen);
- }
sfree(disp->hostname);
sfree(disp->unixsocketpath);
if (disp->localauthdata)
smemclr(disp->localauthdata, disp->localauthdatalen);
sfree(disp->localauthdata);
- if (disp->remoteauthdata)
- smemclr(disp->remoteauthdata, disp->remoteauthdatalen);
- sfree(disp->remoteauthdata);
- sfree(disp->remoteauthprotoname);
- sfree(disp->remoteauthdatastring);
sk_addr_free(disp->addr);
sfree(disp);
}
#define XDM_MAXSKEW 20*60 /* 20 minute clock skew should be OK */
-static char *x11_verify(unsigned long peer_ip, int peer_port,
- struct X11Display *disp, char *proto,
- unsigned char *data, int dlen)
+static const char *x11_verify(unsigned long peer_ip, int peer_port,
+ tree234 *authtree, char *proto,
+ unsigned char *data, int dlen,
+ struct X11FakeAuth **auth_ret)
{
- if (strcmp(proto, x11_authnames[disp->remoteauthproto]) != 0)
- return "wrong authorisation protocol attempted";
- if (disp->remoteauthproto == X11_MIT) {
- if (dlen != disp->remoteauthdatalen)
- return "MIT-MAGIC-COOKIE-1 data was wrong length";
- if (memcmp(disp->remoteauthdata, data, dlen) != 0)
- return "MIT-MAGIC-COOKIE-1 data did not match";
+ struct X11FakeAuth match_dummy; /* for passing to find234 */
+ struct X11FakeAuth *auth;
+
+ /*
+ * First, do a lookup in our tree to find the only authorisation
+ * record that _might_ match.
+ */
+ if (!strcmp(proto, x11_authnames[X11_MIT])) {
+ /*
+ * Just look up the whole cookie that was presented to us,
+ * which x11_authcmp will compare against the cookies we
+ * currently believe in.
+ */
+ match_dummy.proto = X11_MIT;
+ match_dummy.datalen = dlen;
+ match_dummy.data = data;
+ } else if (!strcmp(proto, x11_authnames[X11_XDM])) {
+ /*
+ * Look up the first cipher block, against the stored first
+ * cipher blocks for the XDM-AUTHORIZATION-1 cookies we
+ * currently know. (See comment in x11_invent_fake_auth.)
+ */
+ match_dummy.proto = X11_XDM;
+ match_dummy.xa1_firstblock = data;
+ } else {
+ return "Unsupported authorisation protocol";
}
- if (disp->remoteauthproto == X11_XDM) {
+
+ if ((auth = find234(authtree, &match_dummy, 0)) == NULL)
+ return "Authorisation not recognised";
+
+ /*
+ * If we're using MIT-MAGIC-COOKIE-1, that was all we needed. If
+ * we're doing XDM-AUTHORIZATION-1, though, we have to check the
+ * rest of the auth data.
+ */
+ if (auth->proto == X11_XDM) {
unsigned long t;
time_t tim;
int i;
return "XDM-AUTHORIZATION-1 data was wrong length";
if (peer_port == -1)
return "cannot do XDM-AUTHORIZATION-1 without remote address data";
- des_decrypt_xdmauth(disp->remoteauthdata+9, data, 24);
- if (memcmp(disp->remoteauthdata, data, 8) != 0)
+ des_decrypt_xdmauth(auth->data+9, data, 24);
+ if (memcmp(auth->data, data, 8) != 0)
return "XDM-AUTHORIZATION-1 data failed check"; /* cookie wrong */
if (GET_32BIT_MSB_FIRST(data+8) != peer_ip)
return "XDM-AUTHORIZATION-1 data failed check"; /* IP wrong */
if (data[i] != 0) /* zero padding wrong */
return "XDM-AUTHORIZATION-1 data failed check";
tim = time(NULL);
- if (abs(t - tim) > XDM_MAXSKEW)
+ if (((unsigned long)t - (unsigned long)tim
+ + XDM_MAXSKEW) > 2*XDM_MAXSKEW)
return "XDM-AUTHORIZATION-1 time stamp was too far out";
seen = snew(struct XDMSeen);
seen->time = t;
memcpy(seen->clientid, data+8, 6);
- assert(disp->xdmseen != NULL);
- ret = add234(disp->xdmseen, seen);
+ assert(auth->xdmseen != NULL);
+ ret = add234(auth->xdmseen, seen);
if (ret != seen) {
sfree(seen);
return "XDM-AUTHORIZATION-1 data replayed";
}
/* While we're here, purge entries too old to be replayed. */
for (;;) {
- seen = index234(disp->xdmseen, 0);
+ seen = index234(auth->xdmseen, 0);
assert(seen != NULL);
if (t - seen->time <= XDM_MAXSKEW)
break;
- sfree(delpos234(disp->xdmseen, 0));
+ sfree(delpos234(auth->xdmseen, 0));
}
}
/* implement other protocols here if ever required */
+
+ *auth_ret = auth;
return NULL;
}
/* We have no interface to the logging module here, so we drop these. */
}
+static void x11_send_init_error(struct X11Connection *conn,
+ const char *err_message);
+
static int x11_closing(Plug plug, const char *error_msg, int error_code,
int calling_back)
{
- struct X11Private *pr = (struct X11Private *) plug;
+ struct X11Connection *xconn = (struct X11Connection *) plug;
if (error_msg) {
/*
- * Socket error. Slam the connection instantly shut.
+ * Socket error. If we're still at the connection setup stage,
+ * construct an X11 error packet passing on the problem.
+ */
+ if (xconn->no_data_sent_to_x_client) {
+ char *err_message = dupprintf("unable to connect to forwarded "
+ "X server: %s", error_msg);
+ x11_send_init_error(xconn, err_message);
+ sfree(err_message);
+ }
+
+ /*
+ * Whether we did that or not, now we slam the connection
+ * shut.
*/
- sshfwd_unclean_close(pr->c);
+ sshfwd_unclean_close(xconn->c, error_msg);
} else {
/*
* Ordinary EOF received on socket. Send an EOF on the SSH
* channel.
*/
- if (pr->c)
- sshfwd_write_eof(pr->c);
+ if (xconn->c)
+ sshfwd_write_eof(xconn->c);
}
return 1;
static int x11_receive(Plug plug, int urgent, char *data, int len)
{
- struct X11Private *pr = (struct X11Private *) plug;
+ struct X11Connection *xconn = (struct X11Connection *) plug;
- if (sshfwd_write(pr->c, data, len) > 0) {
- pr->throttled = 1;
- sk_set_frozen(pr->s, 1);
+ if (sshfwd_write(xconn->c, data, len) > 0) {
+ xconn->throttled = 1;
+ xconn->no_data_sent_to_x_client = FALSE;
+ sk_set_frozen(xconn->s, 1);
}
return 1;
static void x11_sent(Plug plug, int bufsize)
{
- struct X11Private *pr = (struct X11Private *) plug;
+ struct X11Connection *xconn = (struct X11Connection *) plug;
- sshfwd_unthrottle(pr->c, bufsize);
+ sshfwd_unthrottle(xconn->c, bufsize);
}
/*
{
int n;
- n = strcspn(display, ":");
+ n = host_strcspn(display, ":");
if (!display[n])
return 0;
n = strcspn(display, ".");
}
/*
- * Called to set up the raw connection.
- *
- * Returns an error message, or NULL on success.
- * also, fills the SocketsStructure
+ * Called to set up the X11Connection structure, though this does not
+ * yet connect to an actual server.
*/
-extern const char *x11_init(Socket *s, struct X11Display *disp, void *c,
- const char *peeraddr, int peerport, Conf *conf)
+struct X11Connection *x11_init(tree234 *authtree, void *c,
+ const char *peeraddr, int peerport)
{
static const struct plug_function_table fn_table = {
x11_log,
NULL
};
- const char *err;
- struct X11Private *pr;
+ struct X11Connection *xconn;
/*
* Open socket.
*/
- pr = snew(struct X11Private);
- pr->fn = &fn_table;
- pr->auth_protocol = NULL;
- pr->disp = disp;
- pr->verified = 0;
- pr->data_read = 0;
- pr->throttled = pr->throttle_override = 0;
- pr->c = c;
-
- pr->s = *s = new_connection(sk_addr_dup(disp->addr),
- disp->realhost, disp->port,
- 0, 1, 0, 0, (Plug) pr, conf);
- if ((err = sk_socket_error(*s)) != NULL) {
- sfree(pr);
- return err;
- }
+ xconn = snew(struct X11Connection);
+ xconn->fn = &fn_table;
+ xconn->auth_protocol = NULL;
+ xconn->authtree = authtree;
+ xconn->verified = 0;
+ xconn->data_read = 0;
+ xconn->throttled = xconn->throttle_override = 0;
+ xconn->no_data_sent_to_x_client = TRUE;
+ xconn->c = c;
/*
- * See if we can make sense of the peer address we were given.
+ * We don't actually open a local socket to the X server just yet,
+ * because we don't know which one it is. Instead, we'll wait
+ * until we see the incoming authentication data, which may tell
+ * us what display to connect to, or whether we have to divert
+ * this X forwarding channel to a connection-sharing downstream
+ * rather than handling it ourself.
*/
- {
- int i[4];
- if (peeraddr &&
- 4 == sscanf(peeraddr, "%d.%d.%d.%d", i+0, i+1, i+2, i+3)) {
- pr->peer_ip = (i[0] << 24) | (i[1] << 16) | (i[2] << 8) | i[3];
- pr->peer_port = peerport;
- } else {
- pr->peer_ip = 0;
- pr->peer_port = -1;
- }
- }
+ xconn->disp = NULL;
+ xconn->s = NULL;
- sk_set_private_ptr(*s, pr);
- return NULL;
+ /*
+ * Stash the peer address we were given in its original text form.
+ */
+ xconn->peer_addr = peeraddr ? dupstr(peeraddr) : NULL;
+ xconn->peer_port = peerport;
+
+ return xconn;
}
-void x11_close(Socket s)
+void x11_close(struct X11Connection *xconn)
{
- struct X11Private *pr;
- if (!s)
+ if (!xconn)
return;
- pr = (struct X11Private *) sk_get_private_ptr(s);
- if (pr->auth_protocol) {
- sfree(pr->auth_protocol);
- sfree(pr->auth_data);
+
+ if (xconn->auth_protocol) {
+ sfree(xconn->auth_protocol);
+ sfree(xconn->auth_data);
}
- sfree(pr);
+ if (xconn->s)
+ sk_close(xconn->s);
- sk_close(s);
+ sfree(xconn->peer_addr);
+ sfree(xconn);
}
-void x11_unthrottle(Socket s)
+void x11_unthrottle(struct X11Connection *xconn)
{
- struct X11Private *pr;
- if (!s)
+ if (!xconn)
return;
- pr = (struct X11Private *) sk_get_private_ptr(s);
- pr->throttled = 0;
- sk_set_frozen(s, pr->throttled || pr->throttle_override);
+ xconn->throttled = 0;
+ if (xconn->s)
+ sk_set_frozen(xconn->s, xconn->throttled || xconn->throttle_override);
}
-void x11_override_throttle(Socket s, int enable)
+void x11_override_throttle(struct X11Connection *xconn, int enable)
{
- struct X11Private *pr;
- if (!s)
+ if (!xconn)
return;
- pr = (struct X11Private *) sk_get_private_ptr(s);
- pr->throttle_override = enable;
- sk_set_frozen(s, pr->throttled || pr->throttle_override);
+ xconn->throttle_override = enable;
+ if (xconn->s)
+ sk_set_frozen(xconn->s, xconn->throttled || xconn->throttle_override);
+}
+
+static void x11_send_init_error(struct X11Connection *xconn,
+ const char *err_message)
+{
+ char *full_message;
+ int msglen, msgsize;
+ unsigned char *reply;
+
+ full_message = dupprintf("%s X11 proxy: %s\n", appname, err_message);
+
+ msglen = strlen(full_message);
+ reply = snewn(8 + msglen+1 + 4, unsigned char); /* include zero */
+ msgsize = (msglen + 3) & ~3;
+ reply[0] = 0; /* failure */
+ reply[1] = msglen; /* length of reason string */
+ memcpy(reply + 2, xconn->firstpkt + 2, 4); /* major/minor proto vsn */
+ PUT_16BIT(xconn->firstpkt[0], reply + 6, msgsize >> 2);/* data len */
+ memset(reply + 8, 0, msgsize);
+ memcpy(reply + 8, full_message, msglen);
+ sshfwd_write(xconn->c, (char *)reply, 8 + msgsize);
+ sshfwd_write_eof(xconn->c);
+ xconn->no_data_sent_to_x_client = FALSE;
+ sfree(reply);
+ sfree(full_message);
+}
+
+static int x11_parse_ip(const char *addr_string, unsigned long *ip)
+{
+
+ /*
+ * See if we can make sense of this string as an IPv4 address, for
+ * XDM-AUTHORIZATION-1 purposes.
+ */
+ int i[4];
+ if (addr_string &&
+ 4 == sscanf(addr_string, "%d.%d.%d.%d", i+0, i+1, i+2, i+3)) {
+ *ip = (i[0] << 24) | (i[1] << 16) | (i[2] << 8) | i[3];
+ return TRUE;
+ } else {
+ return FALSE;
+ }
}
/*
* Called to send data down the raw connection.
*/
-int x11_send(Socket s, char *data, int len)
+int x11_send(struct X11Connection *xconn, char *data, int len)
{
- struct X11Private *pr;
- if (!s)
+ if (!xconn)
return 0;
- pr = (struct X11Private *) sk_get_private_ptr(s);
/*
* Read the first packet.
*/
- while (len > 0 && pr->data_read < 12)
- pr->firstpkt[pr->data_read++] = (unsigned char) (len--, *data++);
- if (pr->data_read < 12)
+ while (len > 0 && xconn->data_read < 12)
+ xconn->firstpkt[xconn->data_read++] = (unsigned char) (len--, *data++);
+ if (xconn->data_read < 12)
return 0;
/*
* If we have not allocated the auth_protocol and auth_data
* strings, do so now.
*/
- if (!pr->auth_protocol) {
- pr->auth_plen = GET_16BIT(pr->firstpkt[0], pr->firstpkt + 6);
- pr->auth_dlen = GET_16BIT(pr->firstpkt[0], pr->firstpkt + 8);
- pr->auth_psize = (pr->auth_plen + 3) & ~3;
- pr->auth_dsize = (pr->auth_dlen + 3) & ~3;
+ if (!xconn->auth_protocol) {
+ xconn->auth_plen = GET_16BIT(xconn->firstpkt[0], xconn->firstpkt + 6);
+ xconn->auth_dlen = GET_16BIT(xconn->firstpkt[0], xconn->firstpkt + 8);
+ xconn->auth_psize = (xconn->auth_plen + 3) & ~3;
+ xconn->auth_dsize = (xconn->auth_dlen + 3) & ~3;
/* Leave room for a terminating zero, to make our lives easier. */
- pr->auth_protocol = snewn(pr->auth_psize + 1, char);
- pr->auth_data = snewn(pr->auth_dsize, unsigned char);
+ xconn->auth_protocol = snewn(xconn->auth_psize + 1, char);
+ xconn->auth_data = snewn(xconn->auth_dsize, unsigned char);
}
/*
* Read the auth_protocol and auth_data strings.
*/
- while (len > 0 && pr->data_read < 12 + pr->auth_psize)
- pr->auth_protocol[pr->data_read++ - 12] = (len--, *data++);
- while (len > 0 && pr->data_read < 12 + pr->auth_psize + pr->auth_dsize)
- pr->auth_data[pr->data_read++ - 12 -
- pr->auth_psize] = (unsigned char) (len--, *data++);
- if (pr->data_read < 12 + pr->auth_psize + pr->auth_dsize)
+ while (len > 0 &&
+ xconn->data_read < 12 + xconn->auth_psize)
+ xconn->auth_protocol[xconn->data_read++ - 12] = (len--, *data++);
+ while (len > 0 &&
+ xconn->data_read < 12 + xconn->auth_psize + xconn->auth_dsize)
+ xconn->auth_data[xconn->data_read++ - 12 -
+ xconn->auth_psize] = (unsigned char) (len--, *data++);
+ if (xconn->data_read < 12 + xconn->auth_psize + xconn->auth_dsize)
return 0;
/*
* If we haven't verified the authorisation, do so now.
*/
- if (!pr->verified) {
- char *err;
+ if (!xconn->verified) {
+ const char *err;
+ struct X11FakeAuth *auth_matched = NULL;
+ unsigned long peer_ip;
+ int peer_port;
+ int protomajor, protominor;
+ void *greeting;
+ int greeting_len;
+ unsigned char *socketdata;
+ int socketdatalen;
+ char new_peer_addr[32];
+ int new_peer_port;
+
+ protomajor = GET_16BIT(xconn->firstpkt[0], xconn->firstpkt + 2);
+ protominor = GET_16BIT(xconn->firstpkt[0], xconn->firstpkt + 4);
+
+ assert(!xconn->s);
+
+ xconn->auth_protocol[xconn->auth_plen] = '\0'; /* ASCIZ */
+
+ peer_ip = 0; /* placate optimiser */
+ if (x11_parse_ip(xconn->peer_addr, &peer_ip))
+ peer_port = xconn->peer_port;
+ else
+ peer_port = -1; /* signal no peer address data available */
+
+ err = x11_verify(peer_ip, peer_port,
+ xconn->authtree, xconn->auth_protocol,
+ xconn->auth_data, xconn->auth_dlen, &auth_matched);
+ if (err) {
+ x11_send_init_error(xconn, err);
+ return 0;
+ }
+ assert(auth_matched);
- pr->auth_protocol[pr->auth_plen] = '\0'; /* ASCIZ */
- err = x11_verify(pr->peer_ip, pr->peer_port,
- pr->disp, pr->auth_protocol,
- pr->auth_data, pr->auth_dlen);
+ /*
+ * If this auth points to a connection-sharing downstream
+ * rather than an X display we know how to connect to
+ * directly, pass it off to the sharing module now.
+ */
+ if (auth_matched->share_cs) {
+ sshfwd_x11_sharing_handover(xconn->c, auth_matched->share_cs,
+ auth_matched->share_chan,
+ xconn->peer_addr, xconn->peer_port,
+ xconn->firstpkt[0],
+ protomajor, protominor, data, len);
+ return 0;
+ }
- /*
- * If authorisation failed, construct and send an error
- * packet, then terminate the connection.
- */
- if (err) {
- char *message;
- int msglen, msgsize;
- unsigned char *reply;
-
- message = dupprintf("%s X11 proxy: %s", appname, err);
- msglen = strlen(message);
- reply = snewn(8 + msglen+1 + 4, unsigned char); /* include zero */
- msgsize = (msglen + 3) & ~3;
- reply[0] = 0; /* failure */
- reply[1] = msglen; /* length of reason string */
- memcpy(reply + 2, pr->firstpkt + 2, 4); /* major/minor proto vsn */
- PUT_16BIT(pr->firstpkt[0], reply + 6, msgsize >> 2);/* data len */
- memset(reply + 8, 0, msgsize);
- memcpy(reply + 8, message, msglen);
- sshfwd_write(pr->c, (char *)reply, 8 + msgsize);
- sshfwd_write_eof(pr->c);
- sfree(reply);
- sfree(message);
- return 0;
- }
+ /*
+ * Now we know we're going to accept the connection, and what
+ * X display to connect to. Actually connect to it.
+ */
+ sshfwd_x11_is_local(xconn->c);
+ xconn->disp = auth_matched->disp;
+ xconn->s = new_connection(sk_addr_dup(xconn->disp->addr),
+ xconn->disp->realhost, xconn->disp->port,
+ 0, 1, 0, 0, (Plug) xconn,
+ sshfwd_get_conf(xconn->c));
+ if ((err = sk_socket_error(xconn->s)) != NULL) {
+ char *err_message = dupprintf("unable to connect to"
+ " forwarded X server: %s", err);
+ x11_send_init_error(xconn, err_message);
+ sfree(err_message);
+ return 0;
+ }
- /*
- * Now we know we're going to accept the connection. Strip
- * the fake auth data, and optionally put real auth data in
- * instead.
+ /*
+ * Write a new connection header containing our replacement
+ * auth data.
*/
- {
- char realauthdata[64];
- int realauthlen = 0;
- int authstrlen = strlen(x11_authnames[pr->disp->localauthproto]);
- int buflen = 0; /* initialise to placate optimiser */
- static const char zeroes[4] = { 0,0,0,0 };
- void *buf;
-
- if (pr->disp->localauthproto == X11_MIT) {
- assert(pr->disp->localauthdatalen <= lenof(realauthdata));
- realauthlen = pr->disp->localauthdatalen;
- memcpy(realauthdata, pr->disp->localauthdata, realauthlen);
- } else if (pr->disp->localauthproto == X11_XDM &&
- pr->disp->localauthdatalen == 16 &&
- ((buf = sk_getxdmdata(s, &buflen))!=0)) {
- time_t t;
- realauthlen = (buflen+12+7) & ~7;
- assert(realauthlen <= lenof(realauthdata));
- memset(realauthdata, 0, realauthlen);
- memcpy(realauthdata, pr->disp->localauthdata, 8);
- memcpy(realauthdata+8, buf, buflen);
- t = time(NULL);
- PUT_32BIT_MSB_FIRST(realauthdata+8+buflen, t);
- des_encrypt_xdmauth(pr->disp->localauthdata+9,
- (unsigned char *)realauthdata,
- realauthlen);
- sfree(buf);
- }
- /* implement other auth methods here if required */
+ socketdatalen = 0; /* placate compiler warning */
+ socketdata = sk_getxdmdata(xconn->s, &socketdatalen);
+ if (socketdata && socketdatalen==6) {
+ sprintf(new_peer_addr, "%d.%d.%d.%d", socketdata[0],
+ socketdata[1], socketdata[2], socketdata[3]);
+ new_peer_port = GET_16BIT_MSB_FIRST(socketdata + 4);
+ } else {
+ strcpy(new_peer_addr, "0.0.0.0");
+ new_peer_port = 0;
+ }
- PUT_16BIT(pr->firstpkt[0], pr->firstpkt + 6, authstrlen);
- PUT_16BIT(pr->firstpkt[0], pr->firstpkt + 8, realauthlen);
+ greeting = x11_make_greeting(xconn->firstpkt[0],
+ protomajor, protominor,
+ xconn->disp->localauthproto,
+ xconn->disp->localauthdata,
+ xconn->disp->localauthdatalen,
+ new_peer_addr, new_peer_port,
+ &greeting_len);
- sk_write(s, (char *)pr->firstpkt, 12);
-
- if (authstrlen) {
- sk_write(s, x11_authnames[pr->disp->localauthproto],
- authstrlen);
- sk_write(s, zeroes, 3 & (-authstrlen));
- }
- if (realauthlen) {
- sk_write(s, realauthdata, realauthlen);
- sk_write(s, zeroes, 3 & (-realauthlen));
- }
- }
- pr->verified = 1;
+ sk_write(xconn->s, greeting, greeting_len);
+
+ smemclr(greeting, greeting_len);
+ sfree(greeting);
+
+ /*
+ * Now we're done.
+ */
+ xconn->verified = 1;
}
/*
* After initialisation, just copy data simply.
*/
- return sk_write(s, data, len);
+ return sk_write(xconn->s, data, len);
}
-void x11_send_eof(Socket s)
+void x11_send_eof(struct X11Connection *xconn)
+{
+ if (xconn->s) {
+ sk_write_eof(xconn->s);
+ } else {
+ /*
+ * If EOF is received from the X client before we've got to
+ * the point of actually connecting to an X server, then we
+ * should send an EOF back to the client so that the
+ * forwarded channel will be terminated.
+ */
+ if (xconn->c)
+ sshfwd_write_eof(xconn->c);
+ }
+}
+
+/*
+ * Utility functions used by connection sharing to convert textual
+ * representations of an X11 auth protocol name + hex cookie into our
+ * usual integer protocol id and binary auth data.
+ */
+int x11_identify_auth_proto(const char *protoname)
{
- sk_write_eof(s);
+ int protocol;
+
+ for (protocol = 1; protocol < lenof(x11_authnames); protocol++)
+ if (!strcmp(protoname, x11_authnames[protocol]))
+ return protocol;
+ return -1;
+}
+
+void *x11_dehexify(const char *hex, int *outlen)
+{
+ int len, i;
+ unsigned char *ret;
+
+ len = strlen(hex) / 2;
+ ret = snewn(len, unsigned char);
+
+ for (i = 0; i < len; i++) {
+ char bytestr[3];
+ unsigned val = 0;
+ bytestr[0] = hex[2*i];
+ bytestr[1] = hex[2*i+1];
+ bytestr[2] = '\0';
+ sscanf(bytestr, "%x", &val);
+ ret[i] = val;
+ }
+
+ *outlen = len;
+ return ret;
+}
+
+/*
+ * Construct an X11 greeting packet, including making up the right
+ * authorisation data.
+ */
+void *x11_make_greeting(int endian, int protomajor, int protominor,
+ int auth_proto, const void *auth_data, int auth_len,
+ const char *peer_addr, int peer_port,
+ int *outlen)
+{
+ unsigned char *greeting;
+ unsigned char realauthdata[64];
+ const char *authname;
+ const unsigned char *authdata;
+ int authnamelen, authnamelen_pad;
+ int authdatalen, authdatalen_pad;
+ int greeting_len;
+
+ authname = x11_authnames[auth_proto];
+ authnamelen = strlen(authname);
+ authnamelen_pad = (authnamelen + 3) & ~3;
+
+ if (auth_proto == X11_MIT) {
+ authdata = auth_data;
+ authdatalen = auth_len;
+ } else if (auth_proto == X11_XDM && auth_len == 16) {
+ time_t t;
+ unsigned long peer_ip = 0;
+
+ x11_parse_ip(peer_addr, &peer_ip);
+
+ authdata = realauthdata;
+ authdatalen = 24;
+ memset(realauthdata, 0, authdatalen);
+ memcpy(realauthdata, auth_data, 8);
+ PUT_32BIT_MSB_FIRST(realauthdata+8, peer_ip);
+ PUT_16BIT_MSB_FIRST(realauthdata+12, peer_port);
+ t = time(NULL);
+ PUT_32BIT_MSB_FIRST(realauthdata+14, t);
+
+ des_encrypt_xdmauth((const unsigned char *)auth_data + 9,
+ realauthdata, authdatalen);
+ } else {
+ authdata = realauthdata;
+ authdatalen = 0;
+ }
+
+ authdatalen_pad = (authdatalen + 3) & ~3;
+ greeting_len = 12 + authnamelen_pad + authdatalen_pad;
+
+ greeting = snewn(greeting_len, unsigned char);
+ memset(greeting, 0, greeting_len);
+ greeting[0] = endian;
+ PUT_16BIT(endian, greeting+2, protomajor);
+ PUT_16BIT(endian, greeting+4, protominor);
+ PUT_16BIT(endian, greeting+6, authnamelen);
+ PUT_16BIT(endian, greeting+8, authdatalen);
+ memcpy(greeting+12, authname, authnamelen);
+ memcpy(greeting+12+authnamelen_pad, authdata, authdatalen);
+
+ smemclr(realauthdata, sizeof(realauthdata));
+
+ *outlen = greeting_len;
+ return greeting;
}
projects / PuTTY.git / blobdiff